An image forming apparatus operates in two operation modes including an operation mode in which printing is executed with a normal toner and an operation mode in which the printing is executed with a decolorable toner decolorized at a prescribed temperature. Such an image forming apparatus operates in a default operation mode if there is no input by a user that instructs the operation mode for the image forming processing. If there is an input by the user, the image forming apparatus operates in an operation mode responsive to the input. The default operation mode may be changed by the input by the user. Therefore, the user needs to confirm on the image forming apparatus whether the operation mode is a desired operation mode when instructing execution of the image forming processing.